1. Field of the Invention
This invention relates to a display system, more particularly, to a helmet mounted display system of the kind which provides a wearer of the helmet with a direct view of a scene forward of the helmet wearer on which is superimposed an intensified image of said scene, e.g. for night vision.
In such a system it is desirable for the components of the system to be relatively positioned so as to distribute the weight of the system around the helmet in a balanced manner, and thereby make the helmet comfortable in use for the wearer. This is difficult to achieve whilst at the same time obtaining an intensified image of the forward scene which is in the same orientation as the wearer's direct view of the forward scene. Known arrangements typically use a so-called Peckham prism which has five internal faces at which reflection of light takes place, and consequently is bulky and has an inconveniently long equivalent length.